<div class="problemindexholder" problemindex="B">
 <div class="ttypography">
  <div class="problem-statement">
   <div class="header">
    <div class="title">
     B. Tell Your World
    </div>
    <div class="time-limit">
     <div class="property-title">
      time limit per test
     </div>
     1 second
    </div>
    <div class="memory-limit">
     <div class="property-title">
      memory limit per test
     </div>
     256 megabytes
    </div>
    <div class="input-file">
     <div class="property-title">
      input
     </div>
     standard input
    </div>
    <div class="output-file">
     <div class="property-title">
      output
     </div>
     standard output
    </div>
   </div>
   <div>
    <p>
     <span class="tex-font-style-it">
      Connect the countless points with lines, till we reach the faraway yonder.
     </span>
    </p>
    <p>
     There are
     <span class="tex-span">
      <i>
       n
      </i>
     </span>
     points on a coordinate plane, the
     <span class="tex-span">
      <i>
       i
      </i>
     </span>
     -th of which being
     <span class="tex-span">
      (
      <i>
       i
      </i>
      ,
      <i>
       y
      </i>
      <sub class="lower-index">
       <i>
        i
       </i>
      </sub>
      )
     </span>
     .
    </p>
    <p>
     Determine whether it's possible to draw two parallel and non-overlapping lines, such that every point in the set lies on
     <span class="tex-font-style-bf">
      exactly one
     </span>
     of them, and each of them passes through
     <span class="tex-font-style-bf">
      at least one
     </span>
     point in the set.
    </p>
   </div>
   <div class="input-specification">
    <div class="section-title">
     Input
    </div>
    <p>
     The first line of input contains a positive integer
     <span class="tex-span">
      <i>
       n
      </i>
     </span>
     (
     <span class="tex-span">
      3 ≤
      <i>
       n
      </i>
      ≤ 1 000
     </span>
     ) — the number of points.
    </p>
    <p>
     The second line contains
     <span class="tex-span">
      <i>
       n
      </i>
     </span>
     space-separated integers
     <span class="tex-span">
      <i>
       y
      </i>
      <sub class="lower-index">
       1
      </sub>
      ,
      <i>
       y
      </i>
      <sub class="lower-index">
       2
      </sub>
      , ...,
      <i>
       y
      </i>
      <sub class="lower-index">
       <i>
        n
       </i>
      </sub>
     </span>
     (
     <span class="tex-span">
      - 10
      <sup class="upper-index">
       9
      </sup>
      ≤
      <i>
       y
      </i>
      <sub class="lower-index">
       <i>
        i
       </i>
      </sub>
      ≤ 10
      <sup class="upper-index">
       9
      </sup>
     </span>
     ) — the vertical coordinates of each point.
    </p>
   </div>
   <div class="output-specification">
    <div class="section-title">
     Output
    </div>
    <p>
     Output "
     <span class="tex-font-style-tt">
      Yes
     </span>
     " (without quotes) if it's possible to fulfill the requirements, and "
     <span class="tex-font-style-tt">
      No
     </span>
     " otherwise.
    </p>
    <p>
     You can print each letter in any case (upper or lower).
    </p>
   </div>
   <div class="sample-tests">
    <div class="section-title">
     Examples
    </div>
    <div class="sample-test">
     <div class="input">
      <div class="title">
       Input
      </div>
      <pre>5<br/>7 5 8 6 9<br/></pre>
     </div>
     <div class="output">
      <div class="title">
       Output
      </div>
      <pre>Yes<br/></pre>
     </div>
     <div class="input">
      <div class="title">
       Input
      </div>
      <pre>5<br/>-1 -2 0 0 -5<br/></pre>
     </div>
     <div class="output">
      <div class="title">
       Output
      </div>
      <pre>No<br/></pre>
     </div>
     <div class="input">
      <div class="title">
       Input
      </div>
      <pre>5<br/>5 4 3 2 1<br/></pre>
     </div>
     <div class="output">
      <div class="title">
       Output
      </div>
      <pre>No<br/></pre>
     </div>
     <div class="input">
      <div class="title">
       Input
      </div>
      <pre>5<br/>1000000000 0 0 0 0<br/></pre>
     </div>
     <div class="output">
      <div class="title">
       Output
      </div>
      <pre>Yes<br/></pre>
     </div>
    </div>
   </div>
   <div class="note">
    <div class="section-title">
     Note
    </div>
    <p>
     In the first example, there are five points:
     <span class="tex-span">
      (1, 7)
     </span>
     ,
     <span class="tex-span">
      (2, 5)
     </span>
     ,
     <span class="tex-span">
      (3, 8)
     </span>
     ,
     <span class="tex-span">
      (4, 6)
     </span>
     and
     <span class="tex-span">
      (5, 9)
     </span>
     . It's possible to draw a line that passes through points
     <span class="tex-span">
      1, 3, 5
     </span>
     , and another one that passes through points
     <span class="tex-span">
      2, 4
     </span>
     and is parallel to the first one.
    </p>
    <p>
     In the second example, while it's possible to draw two lines that cover all points, they cannot be made parallel.
    </p>
    <p>
     In the third example, it's impossible to satisfy both requirements at the same time.
    </p>
   </div>
  </div>
  <p>
  </p>
 </div>
</div>
